I only did one firmware update to my 5D MK II, and that was about December 2008 or early 2009, not long after I got it. Nothing else that affected or interested me has happened since, so I missed out on the updates that caused user issues as well as the ones that subsequently fixed them. If they ever release a update that affects me, I can jump straight to it and I'll get all those updates made over the last three years with it.